Seasonal Influenza is the "flu" that occurs every year sometime between December and March. It changes a little each year, so people who have had the flu or a flu shot in the past will have some resistance to it but need a flu shot each year for better protection.     Avian Influenza is an infection that affects birds and can cause large numbers of birds to die. Avian flu is receiving a lot of attention because there is a possibility that it could change into a form that could infect humans and pass easily from one person to another, causing a pandemic. Pandemic Influenza refers to influenza that is much different than the influenza infections that occurred in previous years. Because it is so different, people have little or no immunity to it and many more people become ill and die. A pandemic may come and go in waves, each of which can last for months at a time. Everyday life could be disrupted due to people in communities across the country becoming ill at the same time. These disruptions could include everything from school and business closings to interruption of basic services such as public transportation and health care. An especially severe influenza pandemic could lead to high levels of illness, death, social disruption, and economic loss. In the event of an influenza pandemic, every member of the community must be prepared.  The Health Department provides planning documents, informational links, and additional resources to help you, your family, your home, your workplace and your community to prepare for pandemic influenza and other public health emergencies.   updated: 3/20/2007